First business trip and first client presentation

So I'm really excited to finally present to a client at our meeting on Friday. I'm a little nervous, but I think some prep time on the plane -- or actually in the airport, since I'll be sleeping on the plane given that it's a 7:30 am flight -- should be enough. I'm also practicing in front of my team, but I'd like to make sure I don't sound stupid before I get in front of them -- in case they decide to take away that responsibility.

But I don't know what to wear. I have a grey dress that goes with a bunch of suit separates, that I was planning to wear. However, after pulling it out for a trial run last week, I realized it's a little on the short side. I'm not sure it's really business appropriate. It's also going to be 59 degrees and cloudy, so it's not the best weather. So question for you all. Should I wear pants or the dress and tights? I have such a hard time deciding =(